Most planaria are aquatic, that is, they live in water.  Bipalium kewense is one of the few which live on land.  Originating in the wet forests of southeast Asia, it has spread throughout the world as stowaways in pots of plant specimens.  It eats earthworms and slugs, among other things.  B. kewense has become well established in the gardens of this part of California.

One never knows what one might find when turning over an object which has been lying on damp ground.  Is it a worm? a slug? or just a slimy mess?

Being negatively phototactic (it likes dark places), it soon begins it unwind as it heads for the nearest shadow.  The head, flattened and wider than the body, is characteristic of planaria in general.

Here we see a planarian eating an earthworm.  The back part of the planarian is coiled over the part of the earthworm which is being digested.  Flatworms must digest their food outside their bodies.

This animal measured at about 25 cm in length.  (Sorry about the archaic inches on the ruler, one uses what is close at hand.)

Look carefully, and you can see the slime trail left behind by the planarian.  It is similar to trails left by slugs and snails.

[Taxonomy : Classification]
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